| Summary: | 碩士 === 國立雲林科技大學 === 工業工程與管理研究所碩士班 === 95 === One of the characteristics of flexible manufacturing systems (FMS) is that they can consider multiple part routings due to alternate machining and alternate sequencing in the processing of parts. It is important to construct a shop flow control to handle the part routing problem in an FMS. In this research, an object-oriented Petri nets combining with OR graphs and A* search algorithm is presented to solve the part routing problem. For each part, the OR routing graph is employed to determine the next machine in which the part will be processed. The machine selection process is guided by the A* heuristic search method under the consideration of both current machine status and selected scheduling rules. The object-oriented colored timed Petri nets of an FMS are used to control parts traveling among machines necessary to visit, send machine selection requests and receive machine selection results for each part, and pass dispatching commands to production equipments and material handling. One example has been used to illustrate the proposed approach. The results show that the proposed approach can effectively cope with the real time dispatching problem for multiple parts with multiple routings.
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